Mineral oil lubricants containing polymers of 1-olefins



Oct. 17, 1950 c. M. FONTANA ET'AL MINERAL OIL LUBRICANTS CONTAINING POLYMERS OF l-OLEFINS Filed Aug. l1, '1948 MPa/afm JNVENTOR.

Q O Qwml u AGEN T Patented Oct. 17, 1950 MINERAL OIL LUBRICANTS CONTAININ G POLYMERS OF I-OLEFIN S Celeste M. Fontana, Pitman, N. J., and Glenn A. Kidder, Harbel, Liberia, assgnors, by mesne assignments, to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation oi New York Application August 11, 1948, Serial No. 43,724

18 Claims.

This invention relates to polymerization of` olefins and relates more particularly to the polymerization of l-olens to produce highly viscous polymer products. The present application is a continuation-in-part of application Serial No. 698,730, led September 23, 1946, now abandoned.

It is known that the branched chain oleiln, isobutene, may be polymerized in the presence l of suitable metal halide catalysts, particularly boron fluoride, with or without the assistance of catalyst promoting agents such as the hydrogen halides, to produce polymer products ranging in viscosity from very light liquids and light lubricating oils to rubbery semi-solids. The viscosity of the product has been found to depend upon the temperature at which the polymerization reaction is carried out, the light products being obtained at room temperature and higher and the heavier products being obtained at temperatures of the order of -40 C. and lower, for example, -80 C. or even 100 C. The heavier products obtained. i. e., those of very high vis- -cosity bordering upon a semi-solid nature, and

even those having rubbery characteristics, have been found to be highly useful as additives or blending agents for admixture with natural mineral oil base stocks to improve their viscosity characteristics, particularly their viscosity indices. Attempts to produce a highly viscous polymer suitable as a viscosity and viscosity index improving blending agent from l-oleflns containing four or more carbon atoms heretofore have not been successful. By l-oleiins containing four or more carbon atoms, we mean any olen containing four or more carbon atoms where the double bond is on a terminal carbon atom and no more than one alkyl substituent is on the carbon atom once removed from the ter.- minal carbon atom. These olefins have the general formula, Rf-CH=CH2, where R is an alkyl atoms. It is another object of this invention to provide blending agents from 1-oielns containing four or more carbon atoms which have novel and improved viscosity and` viscosity index improving qualities. It is another object of this invention to provide polymer products from 1- oleflns containing four or more carbon atoms which have novel and improved thickening powers. Further objects of the invention will become apparent from the following description thereof.

In accordance with the invention, 1-olefins containing four or more carbon atoms are polymerized in high yield by a process which comprises contacting the olefin with aluminum bromide catalyst dissolved in a nonpolymerizing hydrocarbon solvent in the presence of a catalyst promoting agent under selected and correlated reaction conditions. While we are aware that l-olens have been polymerized in the presence of a nonpolymerizing hydrocarbon, aluminum bromide catalyst, and a catalyst promoting agent, we have discovered that, by carrying out the polymerization reaction under selected and correlated reaction conditions, the desired high viscosity and semi-solid polymers can be obtained. Our invention is characterized in that the l-olefin polymer products obtained will have thickening powers at 210 Fahrenheit above 5 and as high as 23.

In setting forth the characteristics of the lolen polymer products of the invention, we have found it useful to employ the concept of thickening power and relative thickening power since, at high viscosities, the concepts of viscosity and viscosity index are no longer satisfactory due to the diiiiculty orimpossibility of directly measuring viscosities. By thickening power of the loleiin polymers, we mean the relationship expressed by the equation 100 kinematic viscosity of oil blend group containing at leest two carbon atoms. While viscous polymers may be produced from these olelns, the polymers obtained are not comparable with those obtained from isobutene because their viscosity indices or viscosity index improving qualities are insumciently high to result in satisfactory improvement in the viscosity index of the base stock.

It is an object of this invention to provide an improved process for the polymerizationof 1- olens containing four or more carbon atoms. It is another object of this invention to provide highly viscous and semi-solid polymer products from l-oleiins containing four or more carbon polymer in blend o kinematic viscosity of base oilwhere:

"TP is the thickening power;

% polymer in blend" is the percent by Weight of the polymer blended with a base stock lubricating oil;

Kinematic viscosity of oil blend is the viscosity in centistokes of the blend of base stock lubricating oil and polymer; and

Kinematic viscosity of base oil is the viscosity in centistokes of the base stock lubricating oil.

By 'I'Pzio and TPion, we mean thethickening power, as defined above, where theviscosities of 3 the blends and the base stock lubricating oils are measured at 210 F. and 100 F., -respectively. By relative thickening power, we mean the ratio ot the thickening powers measured at 210 F..

and 100 F., expressed mathematically as Tiki RTP- TPM where IRTP is relative thickening power.

The thickening power is closely related to intrinsic viscosity and is a measure of the molecular weight and viscosity of the polymer. Relative thickening power is closely related to viscosity index and is a measure oi the change in viscosity with change in temperature. It will be realized that those polymers having larger values lof relative thickening power will be superior with respect to change in viscosity with temperature.

Our invention is predicated on our discovery that polymers having high thickening powers may be obtained by employing selected and correlated reaction conditions within speciiied lim ts. We have discovered that the ratio of promoter to aluminum bromide catalyst is an important variable, and that a deflnte minimum ratio is required in order to obtain the products of high thickening power. An excess of promoter over this required minimum ratio may be employed but We have discovered that, as the ratio of promoter to aluminum bromide catalyst is increased, the thickening power of the polymer begins to decrease. Preferably, we do not employ more than 1.6 moles of catalyst promoter per mole of aluminum bromide catalyst. However, it is essential that at least 0.05 mole of catalyst promoter per mole of aluminum bromide catalyst be employed. Preferably, we employ a ratio of between about 0.08 and 1.2 moles of catalyst y promoter per mole of aluminum bromide catalyst.

We have discovered additionally that the high thickening power polymers are obtained only when the instantaneous l-olefln monomer concentration in the reaction mixture is maintained at a low value. Since the rate at which the lolefin polymerizes, and therefore the amount of l-olen monomer in the reaction mixture at any one time, is not readily ascertainable, we prefer to express this concentration in terms of the rate at which the l-olen is added to the reaction mixture containing diluent. promoter, and aluminum bromide catalyst. We have discovered that it is necessary to employ a rate of addition of l-oeiin not greater than 4.0 moles per mole of aluminum bromide catalyst per minute. For polymers of very high thickening power, we prefer to employ a rate of addition not greater than about 2.5 moles per mole of aluminum bromide catalyst per minute. Where higher rates of addition are ernployed, polymer products of inferior thickening power are obtained. It is believed that the effect oi' rate of addition is not due to incomplete polymerization of olen, since the polymerization reaction is essentially complete in less than one minute with essentially 100% conversion to polymer product of desired thickening power. While we do not wish to be limited to the consequences of any theory, the eil'ect is believed to be due to a chain transfer reaction with monomeric olen resulting in low molecular weight products when the instantaneous 1olen monomer concentration is high.

Another variable we have found to be of signiilcance is the olen to catalyst ratio, i. e., the total amount of l-olen polymerized per unit amount oi' aluminum bromide employed. We

have discovered that l-olenn polymers having high thickening powers may be obtained by employing olen to catalyst ratios in excess of 5 moles of oletln per mole of aluminum bromide catalyst. Preferably, however, we employ higher ratios of oleiin to catalyst in order to obtain maximum utilization of the catalyst, for example, ratios of oleiin to catalyst between l0 and 90 moles of olen per mole of catalyst. Further, we prefer to employ ratios not in excess of about moles of olefin per mole of catalyst, since above these values the thickening powers of the l-olen polymer products obtained decrease. Most satisfactory results are obtained with ratlos between 20 and 75 moles of olen per mole of catalyst.

The temperaturer at which the polymerization reaction is carried out affects the thickening power of the polymer product and we have discovered that, contrary to general belief, the viscosity and molecular weight. and consequently the thickening power, do not increase with decreasing temperature of reaction, but increase to reach a maximum value after which they decrease with decreasing temperature. The temperature at which this maximum value of thickening power of polymer product is obtained and the range of temperatures in which high values of thickening power of polymer product are obtained increase with increasing carbon content of the olen monomer. For four carbon atom 1- oleiin, i. e., l-butene, polymers having high thickening powers are obtained at temperatures between about 10 C. and 45 C., and more particularly at temperatures between about 25 C. and 40 C.. with the polymers of greatest thickening power being obtained at a temperature of about 35 C. For tive carbon atoms l-olens, for example, 1pentene, polymers having high thickening powers are obtained at temperatures between about 0 C. and 40 C., and more particularly at temperatures between about 15 C. and 35 C., with the polymers of greatest thickening power being obtained at about 30 C. For l-olens containing eight or more carbon atoms, for example, l-octene and higher oleiins, polymers of high thickening power are obtained at temperatures between about +20 C. and 35 C., and more particularly at temperatures between about 0" C. and 30 C., with the polymers of greatest thickening power being obtained at about 20 C.

It will be obvious to those skilled inthe art that, in order to obtain a l-oefln of a desired specified thickening power, selection and correlation of the reaction variables within the limits set forth above will be made. Thus, where l-olefin polymer products have thickening powers at 210 F. of 23 are desired, the most favorable values for the reaction variables will be selected. Where l-olefin polymer products of lesser thickening power are desired, the most favorable value for one or more of the variables may be selected with less favorable values for the other variables being selected Alternatively, less favorable values for all of the variables may be selected to obtain loleiin polymer products of a` speciiied lesser thickening power. The selection and correlation of these variables is within the skill of those versed in the art in the light of the discussion contained herein.

The process of the invention may be applied to any l-olen as hereinbefore defined. Examples of such l-oleflns are l-butene, l-pentene, 1- hexene, l-heptene, l-octene, and other l-oleiins up to and including those containing 20 or even y spect to the general formula, R-CH=CH:, R

will contain two carbone atoms in the case of 1- butene, R will contain three carbon atoms in the case of 1-pentene, etc.

l-butene and l-pentene may be suitably obtained from C4 and C5 reilnery streams. Higher molecular weight oleilns may be suitably obtained by dehydration of the corresponding alcohol or may be obtained from cracking still gases,Fisher Tropsch cuts, etc. Mixtures of 1oleilns may also be employed, and the l-oleiln stream may contain saturated hydrocarbons. It is desirable to employ the l-olens as tree as possible oi isoparafns, olens containing two alkyl groups on the carbon atom once removed from the terminal carbon atom. and 2-olellns, since the presence of these compounds tends to reduce the thickening power and the relative thickening` power oi the polymer product. Olefin streamscontaining up to a total oi about of these compounds, however, may be employed.

Included among oleilns containing two alkyl groups on the carbon atom once removed from the terminal carbon atom is isobutene. While isobutene may be polymerized by other processes to produce polymer products of high viscosity, the present process, as applied to isobutene, does not produce a polymer of high thickening power, producing rather, a light oil. Further, these other processes producing a high viscosity polymer from isobutene, when applied to the polymerization of l-oleiins, do not produce a polymer of high thickening power, but produce, rather, a light oil.

The concentration of dissolved aluminum bromide in the nonpolymerizing hydrocarbon solvent should be sufficiently high to catalyze the polymerization reaction. An upper limit to catalyst concentration, however, may be governed by the olelin-catalyst ratio, i. e., at high oleiln-catalyst ratios, large amounts of 1oleilns will be added to the reaction mixture containing a high concentration of dissolved aluminum bromide thereby providing a highly viscous mixture which is difficult to handle during the later operations of clarification, solvent recovery, etc. Preferably, we employ a catalyst concentration, based upon the total nonpolymerizing hydrocarbon in the f reaction mixture, of between 0.1 and 1.5 mole per cent. However, it will be understood that the maximum concentration oi aluminum bromide that may be employed will be limited only by the solubility of the aluminum bromide in the hydrocarbon at the temperature employed.

In carrying out the invention, we prefer to employ hydrogen bromide as the catalyst prometing agent. However. bromo-alkanes containing at least three carbon atoms, such as propyl, isopropyl, butyl, isoanrvl, etc., bromo-alkanes may be employed. Also, compounds which react under the conditions of thepolymerization reaction, for example, by reaction with aluminum bromide to produce hydrogen bromide are also effective. The mechanism oi the catalyst promoting effect of the bromo-alkanes is not well understood, although it appears that, since aluminum bromide is known to catalyze the dehydrobromination of bromo-alkanes, dehydrobro mination of the bromo-alkanes may occur to form olens and hydrogen bromide, the hydrogen bromide thereupon acting as the elective promoter. However, at low temperatures, 4equilibria do not favor dehydrobromination, and, at

these temperatures it is possible that the promoting eiect may be due to co-polymerization of 'the Ybromo-alkanes to produce a polymer and hydrogen bromide. It is also possible that the bromo-alkanes are in themselves promoting agents, and, where hydrogen bromide is em- Y ployed as the promoter, a bromo-alkene is formed by reaction of the hydrogen bromide and the 1- oleiln which thereupon acts as the effective catalyst promoting agent. When employing bromoalkanes, the mole ratio oi these compounds to dissolved aluminum bromide will be the same numerically as where hydrogen bromide is employed, although if compounds which react under the conditions of the polymerization reac tion to produce hydrogen bromide are employed, an amount will be used which will give the desired ratio oi promoter, measured as hydrogen bromide, to aluminum bromide catalyst.

It is possible to carry out the reaction either as a batch reaction or as a continuous reaction. In batch operation, the l-oleiln may be added to the reaction vessel containing the dissolved aluminum bromide plus the proper amount of promoter. In this type oi operation, the reaction vessel will contain a known amount of dissolved aluminum bromide and the l-olefln may be. added thereto at the desired rate. In continuous operation. the l-olefin and the dissolved aluminum bromide, plus the proper amount of promoter in admixture with the l-olefin or as a separate stream, are added simultaneously to the reaction vessel, and a stream of reaction mixture is removed continuously therefrom. In the latter type of operation, the reaction vessel will be lled with reaction mixture and, for any given ratio of rates of flow of the respective streams thereto, will contain a known quantity of dissolved aluminum bromide. Thus, suitable adjustment of the rates of flow of the respective streams will result in addition of 1-olen to the reaction vessel at the desired rate with respect to the amount of aluminum bromide.

The catalyst solution may be prepared by dissolving the aluminum bromide in any suitable type of non-polymerizing hydrocarbon solvent. Examples of suitable hydrocarbon solvents are the saturated hydrocarbon solvents such as ethane, propane, normal butane. etc. Mixtures of one or more solvents may also be employed, if desired, for preparing the catalyst solution.

It is preferred to carry out the polymerization reaction in the presence of a diluent for the l olen. The saturated hydrocarbons employed as solvents for the aluminum bromide are satisfactory as diluents. If desired, mixtures of hydrocarbons may be used as diluents.

, In both batch and continuous operation, one type of hydrocarbon may be employed as diluent and another type of hydrocarbon may be employed as solvent for the aluminum bromide, or

' a mixture of two or more hydrocarbons may be employed as diluent and as solvent. However, it will be more convenient to employ the same single hydrocarbon as diluent and as solvent, particularly in'large scale operations, in order to simplify the later procedures'of recovering the diluent and solvent for reuse. In the case of low temperature polymerization, on the other hand, it may frequently be advantageous to use a solvent of moderate voltatility, such as normal butane, to dissolve the catalyst and a highly volatile diluent, such as ethane, capable of use for evaporative cooling, to control the temperature of the polymerization reaction mixture. The catan lyst solution may be added to part of all of the diluent, whether or not the same type of hydrocarbon is used as solvent and as diluent, and the mixture will serve in the capacity of both catalyst solution and diluent.

The amount of nonpolymerizing hydrocarbon to be employed as solvent and as diluent may be the same as conventionally employed in olefin polymerization reactions. We may use nonpolymerizing hydrocarbon in the amount between about 3 and 8 moles per mole of l-olen. However, larger or smaller ratios may be employed as desired.

In carrying out the polymerization reaction, the feed streams, before being charged to the reactor, are preferably brought to the desired re= action temperature. The polymerization reaction is exothermic, and the reaction mixture may be maintained at the desired temperature by means of external heat exchangers as, for example, by employing a jacketed reaction vessel or heat exchanger coils within the reaction vessel through which suitable refrigerants may be passed. If desired, evaporative cooling may be employed.

Pressures to be employed should be sufcient to keep the solvent and diluent in the liquid phase at the particular temperature of polymerization selected. The l-olen may be admitted to the reactor in either the gaseous phase or the liquid phase.

Following polymerization, the reactor efliuent may be treated by any suitable procedure for removal of catalyst tar, if tar is present, and dissolved catalyst. For example, catalyst tar, if present, may be removed by settling. The reactor effluent may then be treated with water, alkali, alcohol, etc., to inactivate the aluminum bromide after which the reaction products of the dissolved aluminum bromide and the inactivating agent may be removed by washing, filtering, or other suitable means. It is desirable to clarify the reaction products and this may be effected with a clay such as bentonite. Following clarification, the reaction effluent may be subjected to fractionation, steam distillation, gas stripping, or other suitable procedure to remove solvent, diluent, and any light hydrocarbon reaction products or light polymer products from the desired polymer product. Where fractionation is employed to remove from the desired polymer product any light polymer products that may be formed, W pressure may be used to obtain effective separation without the use of high temperatures conducive to cracking of the desired polymer product. Temperatures not above about 350 C. are satisfactory, and the pressure within the apparatus may be progressively decreased, as the fractionation proceeds, to a pressure of about one millimeter of mercury at the end of the fractionation operation. However, effective separation of light polymer products may be effected by heating and fiushing with an inert gas such as nitrogen.

Hydrogen bromide or other promoter contained in the polymerization reaction effluent will be removed during treatment for removal of aluminum bromide catalyst. Should any promoter remain in the reaction effluent it will be largely removed during fractionation or otherwise for the removal of solvent, diluent, or light hydrocarbon reactionproducts. Fractionation, or gas flushing, for removal of light polymer products from the desired polymer product willfremove any traces of promoter not previously removed.

Where the polymer products are to be employed as blending agents or otherwise employed in admixture with a hydrocarbon oil, a hydrocarbon oil may be admixed with the reaction eliluent prior to removal of solvent and diluent in order to facilitate handling of an otherwise highly viscous or semi-solid product.

While the products of the invention may be used for various purposes, they are particularly useful as viscosity index improving agents for mineral lubricating oils. The polymer products of the invention are characterized by their ability to produce blends having viscosity indices between 180 and 150 where the base stock has a viscosity index between about and 120. Where the base stock has a lower viscosity index, a greater proportionate increase in the viscosity index of the blend will be obtained.

The accompanying drawing is a flow sheet schematically illustrating one method of carrying out the polymerization reaction.

Referring now `to the drawing, l-olefin feed enters the system through line I5 and is pumped by means of pump IB to polymerization reactor il. Before entering the polymerization reactor, the l-olen feed passes through heat exchanger i9 where it is heated or cooled to the desired reaction temperature. The solvent-diluent feed enters the system through line 20 and is pumped by means of pump 2l to the polymerization reactor Il, being heated or cooled to the desired reaction temperature before entering the reactor by passage through heat exchanger 24.

Aluminum bromide catalyst dissolved in a saturated hydrocarbon solvent enters polymerization reactor il from reservoir 25 through line 26 connected to solventdiluent feed line 20.

Hydrogen bromide promoter is fed to the system through line 2l connected to line 20. Recycle solvent-diluent obtained in the manner to be hereinafter described enters line 20 through line 29 and passes into polymerization reactor Il. Line 29 is provided with flow control valve 3D and solvent-diluent feed line 20 is provided with flow control valve 3| for control of the solvent-diluent entering the reactor Il. Olen feed line I5 is provided with iiow control valve 32, hydrogen bromide feed line 21 is itted with flow control valve 34, and aluminum bromide line 26 is fitted with fiow control valve 35. By suitable manipulation of these flow control valves, the proper ratio of hydrogen bromide to aluminum bromide, the desired concentration of aluminum bromide, and the proper rate of 1-olen feed to aluminum bromide concentration is obtained in the polymerization reactor Il.

The solvent-diluent feed containing the dissolved aluminum bromide and hydrogen bromide is intimately mixed with the lolen in the reactor I'l by means of stirrer 36. To maintain the reactants at the desired polymerization temperature, a suitable heat transfer medium is conducted through jacket 31.

The polymerization reaction products are withdrawn from the reactor Il through line 38 and are passed to settler 39 wherein any tar formed during the polymerization reaction settles to the bottom, from which it may be withdrawn through line 40. If desired, the tar may be sent to a recovery system (not shown) for recovery of aluminum bromide.

The polymerization reaction mixture leaves the top of the settler 39 through line 4l and is passed to mixing vessel 42 where it is admixed with a solution of alcohol and water entering the vessel passed to a recovery system (not shown) for recovery of alcohol. water, and bromine. t

The hydrooarbonreaction mixture leaves the top of the settler through line 49 and is pumped by means of pump 50 through clay chambers 52 and 53 for clarification. Chambers 52 and 53` are connected in paralel and provided withsuitable valves in order that continuous operation may be obtained by leaving one chamber on stream while the other chamber is taken ofi' stream for refilling or for regeneration of the clay. Steam or other medium for regeneration of the clay may enter through line 54 and leaves chambers 52 and 53 through lines 55 and 58,

respectively. i

The clarified products from the claychambers pass through line 51 and arepumped by means of pump 59 to fractionation column 60. Where l The above described procedure is susceptible of various modications. For example. in place of employing the clay` chambers 52 and 53, the

`polymerization reaction products in line I8 may be clarified by admlxingwith clay and thereafter filtering the clay therefrom. Additionally, if desired, the polymerization products issuing as bottoms from the fractionation column 65 may be steam distilled, gas flushed, or otherwise treated for removal of any light polymer products. These and other modifications are possible, and they. as

well as the necessary provision of apparatus and lines, may readily be made by those skilled in the art.

Our invention will be further illustrated by the following examples:

EXAMPLES 1 TO '7 t In these examples, l-butene was polymerized by passing l-butene, aluminum bromide catalyst i dissolved in liquid normal butane, and hydroven the polymer products are to be employed subsequently in admixture with a hydrocarbon oil, a light hydrocarbon oil may be admixed with the reaction products from line 6i connected to line 51. The solvent-diluent and any catalyst promoter are removed as overhead from fractionation column 60 through line 62. The overhead passes through condenser 64 wherein the solventdiluent is condensed and `the `condensate is pumped by pump 55 to receiver 65. From receiver 55, the solvent-diluent is` pumped by pump 61 through line 29 to line 20 for recycle to the polymerization reactor i1. The recycle solventdiluent may contain some hydrogen bromide which enters the polymerization reactor in addition to the hydrogen bromide fed through the reactor from line 21. Accordingly, this amount of hydrogen bromide must be taken into account when controlling the amount of hydrogen bromide fed from line 21 to obtain the desired ratio of hydrogen to aluminum bromide.

The bottoms from fractionaton column 50 comprise the desired polymer product and any light polymer products formed during the reaction. The bottoms are transferred to fractionation column 69 through line 1li where the light polymer products are removed as overhead through line 1I and condensed in condenser 12, to be utilized as desired. The desired polymer products is removedas bottoms from column 69 through line 14.

bromide promoter continuously to a reaction vessel provided with a cooling coil and a stirrer. The

`three streams were brought to reaction temperature prior to entering the reactor. The; runs were made at various temperatures, but the other reaction conditions were constant for each example and were as follows:`

Ratio of,promoter to catalyst-1.0 mole of HBr per mole of AlBra. Ratio `of oleiln to catalyst-50 moles of l-butene per mole of AlBra. Rate of addition of olefin-0.83 mole of l-butene per mole of AlBr; per minute.

A stream of reaction eilluent was removed continuously from the reactor and admixed. with isopropyl alcohol and water to react with the aluminum bromde catalyst.` The hydrocarbon phase of the mixture was separated from the alcoholwater phaseY and thereafter the butane solvent was evaporated from the hydrocarbon phase.`

The final polymer product was obtained as bottoms by fractionating the hydrocarbon phase at a top temperature of 150 C. and a pressure of 3 mm. of mercury. The final polymer products were obtained, as in all the other examples appearing hereinafter, in a yield of at least 98% of the l-butene charged to the reactor.

The polymer products were admixed in an amount of 2% by weight with a neutral lubricating oil base stock having a viscosity at 210 F. of 5.08 centistolvs and a viscositv index oi'` 113. The viscosities of the blended oils were determined at 100 F. and 210 F., and 'rhe\thicken'ng powers calculated from the expressions given hereinabove.

Table I lists the temperatures of polymerization, the viscosties and viscosity infices of the blends, and the thickening powers of the polymer products.

Tabl.. l

Viscosit 'oiBlcnd THLQR Relative "emper- Viscosity Pol mer Thick- Example No. nime Conti- Centi- [nder of y enimz C. Stokes stokes Blend Power oi at at Polymer 100 F. 210 F. 100 F. 210 F.

-m 42. 3 7. i8 1'14 8. 1 7. 5 0. 93 -21 4?. 3 7.14 133 8.1V .'I 4 0. 91 -30 50.4 8. 58 139 11.9 11 4 0.96 -30 60.4 8.64 140 11.9 11.5 0.91 -30 51. B 8. R2 140 12. 5 l2. 0 0. 96 -40 52. 4 8. all 138 l2. 7 11.9 0. 94 -40 45. 6 7. 70 135 9. 7 9. 0 0. 93

11 ExAMPLEsa 'ro 15 In these examples, l-butene was polymerized in the same manner as described in connection with the previous examples. However, in these examples, the ratio of promoter to catalyst was varied. The other reaction conditions were the same for each example and were as follows:

were determined in the same manner as hereinabove described.

Table III gives the rates of addition of oleiln, expressed as moles of l-butene per mole of aluminum bromide catalyst per minute, and the viscosities and viscosity indices of the blends and thickening powers of the polymer products.

Temperature- 30 C.

Ratio of olefin to catalyst- 50 moles of l-butene per mole of AlBra.

Rate of addition of denn- 0.83 mole of l-butene per mole of AlBra per minute.

The thickening powers of the products were determined similarly as in the preceding examples.

The reaction conditions of promoter to catalyst, expressed as moles of hydrogen bromide per mole 'of aluminum bromide, the viscosities and viscosity indices of the blends, and the thickening powers of the polymer products are given in Table II.

In these examples, butene-l was polymerizedv in the same manner as described in the preceding examples. 'I'he olefin to catalyst ratio, i. e., the ratio of the amount of l-butene to the amount of aluminum bromide catalyst, was varied but the temperature and the ratio of promoter to catalyst were the same for each example as follows:

Temperature- 30 C. Ratio of promoter to catalyst-0.40 mole of HBr per mole of AlBr-a.

The rate of addition oi oleiln to catalyst was Table II Viscosity of Blend Thickening Relativ Pro- Power o! moter Viscosit Po u Thick- Example No. Cm st Centi- Centl- Index o ym ening Ro stokes stakes Blend Power oi.' at at Polymer 100 F. 210 F. 100 F. 210 F.

EXAMPLES 16 T0 19 50 varied such that the entire amount of olen was l-butene was polymerized similarly as in the preceding examples. The rates of addition of lbutene were varied but the other reaction conditions were the same for each example as follows: Temperatura- -30 C.

Ratio of promoter to catalyst-0.40 mole of HBr per mole of AlBra. Ratio of olefin to catalyst-50 moles of i-butene per mole of AlBra.

The thickening powers of the polymer products added to the polymerization reactor within sixty minutes. The thickening powers of the polymer A products were determined as described hereinabove.

Table IV gives the ratio of olefin to catalyst, expressed as moles of l-butene per mole of aluminum bromide, the rate of addition of olefin, expressed as moles of l-butene per mole of aluminum bromide per minute, the viscosities and viscosity indices of the blends, and the thickening powers of the polymer products.

EXAMPLE 2s In this example, l-butene was polymerized under the following reaction conditions:

Temperature- 35 C.

Ratio of promoter to catalyst-0.24 mole of HBr per mole of AIBrs.

Rate of addition of olefin-0.83 mole of l-butene per mole of AlBr; per minute.

Ratio of olefin `to catalyst-50 moles of l-butene per mole of AlBn.

The thickening power of the polymer product was determined as in the preceding examples. The viscosities and viscosity indices of the blend and the thickening power of the polymer product are as follows: i

Viscosity of blend at 100 Iii-62.4 centistokes. Viscosity of blend at 210 F.10.88 centistokes. Viscosity index of blend-144.

Thickening power of polymer at 100 F.-16.5. Thickening power of polymer at 210 F.16.5. Relative thickening power of polymer-1.0.

EXAMPLE 27 In this example, l-butene was polymerized under the following reaction conditions:

Temperature- -35.5 C.

Ratio of promoter to catalyst-1.43 moles of HBr per mole of AlBra.

Rate of addition of olefin- 0.196 mole of 1-butene per mole of AlBre per minute.

Ratio of oleiin to catalyst-19.6 moles of l-butene per mole of AlBrs.

EXAMPLE 28 In this example, l-pentene was polymerized as described in connection with the previous examples. The reaction conditions were:

Ratio of promoter to catalyst-1.51 moles of HBr per mole of AlBrz.

Rate of addition of olefin-0.252 mole of 1-pentene per mole of AlBrs per minute.

Ratio of olefin to catalyst-53.2 moles of 1-pentene per mole of AlBra.

The polymer product was admixed with a lubricating oil base stock as in Example 27. The viscosities and viscosity index of the blend and the thickening process of the polymer prod4 ucts are as follows:

Viscosity of blend `at 100 F.35.09 centistokes. Viscosity of blend at 210 lit-6.38 centistokes. Viscosity index of blend-138.

Thickening power of polymer at 100 F.-8.18. Thickening power of polymer at 210 F.-7.40. Relative thickening power-0.91. i

EXAMPLES 29 TO 32 In these examples, l-octene was polymerized in the same manner as described in connection with the previous examples. The polymer product was admixed with a lubricating oil base stock as in Example 27. The reaction conditions, the viscosities and viscosity indices of the blends, and the thickening process of the polymer products are listed in Table V.

Table V Example No 29 30 31 32 Temperature, C 0 0 0 0 Ratio oi Promoter to Catalyst, Moles o( HBr per mole of AlBr l. 53 l. 50 l. 50 1. 50 Rate oi Addition of Oleiln, Moles l octane per mole oi' AiBrx per minute 0. 192 0. 201 0. 177 0. 196 Ratio o! Oleiin to Catalyst, Moles of l-octene per mole of AlBr: 23. 0 28. 8 18. 6 13. 6 Viscosity of Blend at l00 F., Centistokes 44. 2 41. 0 35. 0 47. 8 Viscosity of Blend at 210 F Centistokes 8. 48 7. 64 6. 50 8. 77 Viscosity Index of Blend 149 145 141 146 Thickening power oi Polymer at F 13. 2 1l. 5 8. 1 14. 9 Thickening power of Polymer at 13. 6 1l. 3 7. 8 14. 3 Relative Thickening Power l. 03 0. 98 0. 96 0. 96

EXAMPLES 33 TO 35 In these examples, 1decene (Example 33), 1- dodecene (Example 34), and l-cetene (Example 35) were polymerized in the same manner as described in connection with the previous examples. The polymer Vproduct was admixed with a lubrieating oil base stock similarly as in Example 27. The table lists the reaction conditions, the viscosities and viscosity indices of the blends, and the thickening powers of the polymer products.

Table VI Example No 33 34 35 Temperature, "C 0 0 0 Ratio oi Promoter to Catalyst, Moles of HBr per mole of AlBra 150 150 150 Bate of Addition of Olefin. Moles of Oleiin per Mole of AlBr; per minute 0.195 0.195 0.180 Ratio of Olen to Catalyst, Moles of Olen r Mole of AlBr; 46. 8 46. 8 13. 5 V scosity of Blend at 100 F., Centistokes. 39.3 40. 7 37. 5 Viscosity of Blend at 210 F., Centistokes y-. 7.36 7. 84 7.16 Viscosity Index of Blend 149 147 Thickening Power of Polymer at 100 F.- l0. 6 11. 4 9.6 Thickening Power of Polymer at 210 F.. 10.5 11.9 9. 9 Relative Thickening Power 0. 99 1. 04 1.03

EXAMPLE 36 In this example, a mixture of oleiins was polymerized in the same manner as hereinbefore described. The mixture contained the following components in volume per cent:

30% l-octene 20% 1decene 20% li-dodecene 10% 1-tetradecene 10% l-hexadecene 10% 1octadecene The polymer product was admixed with a lubricating oil base stock as described in Example 27.

Table VII gives reaction conditions, viscosities and viscosity index of the blend, and the thickening powers of the polymer product.

Table VII Temperature, C 0C. Ratio ol Promoter tovCatalyst, Moles of HBr por mole of 1 5 AIBr-i i Rate of Addition of Olefin, Moles of Olefln per mole of AlBn per minuta .188 Ratio of Olefin to Catalyst, Moles of Olefln per mole of AlBn. 22. 7 Viscosity of Blend at 100 F., Centistokes 34.4 Viscosity of Blend at 210 F.. Centxstokes 6. 40 Viscosity Index of Rlend 141 Thickening Power of Polymer at 100 F 7. 7 Thickening Power of Polymer at 210 F 7. Relative Thickening Power 0. 97

Having thus described our invention, it is to be understood that such description has been given by way of illustration and example only and not by way of limitation, reference for the latter purpose being had to the appended claims.

We claim:

1. A process for effecting the polymerization of an olen having the formula R CH=CH2 wherein R is an alkyl group having at least two carbon atoms, which comprises contacting said olen with aluminum bromide catalyst dissolved in a non-polymerizing hydrocarbon solvent, in a polymerization reaction zone, in the presence of hydrogen bromide, in proportions such that, vduring the course of the reaction in said polymerization reaction zone, the mole ratio of hydrogen bromide to dissolved aluminum bromide will be between about 0.05 and 1.6 and the rate of addition of oleiin to dissolved aluminum bromide will be not greater than about 4 moles per mole of dissolved aluminum bromide per minute.

2. A process for effecting the polymerization of an olen having the formula wherein R is an alkyl group having at least two carbon atoms, which comprises contacting said olefin, aluminum bromide catalyst dissolved in a non-polymerizing hydrocarbon solvent, and hydrogen bromide in a polymerization reaction zone, in proportions such that, during the course of the reaction in said polymerization reaction zone, the mole ratio of hydrogen bromide to dissolved aluminum bromide will be between about 0.08 and 1.2, the rate of addition of olefin to dissolved aluminum bromide will be not greater than about 2.5 moles per mole of dissolved aluminum bromide per minute, and the amount of olefin will be between about l and 90 moles per mole of dissolved aluminum bromide. .y

3. A process for effecting the polymerization of l-butene, which comprises contacting said 1- butene, aluminum bromide catalyst dissolved in a non-polymerizing hydrocarbon solvent, and hydrogen bromide in a polymerization reaction zone, in proportions such that, during the course of the reaction in said polymerization reaction zone, the mole ratio of hydrogen bromide to dissolved aluminum bromide will be between about 0.05 and 1.6, the rate of addition of l-butene to dissolved aluminum bromide will be not greater than about 4 moles per mole of dissolved aluminum bromide per minute, and the amount of 1- butene will be between about 5 and 90 moles per mole of dissolved aluminum bromide, and maintaining said polymerization reaction zone at a temperature of between about C. and 45 C 4. The process of claim 3 wherein the temperature is between about 25 C. and 40 C.

5. The process of claim 3 wherein the temperature is about 35 C.

6. A process for effecting the polymerization of 1pentene, which comprises contacting said 1- pentene, aluminum bromide catalyst dissolved in a non-polymerizing hydrocarbon solvent, and hydrogen bromidein a polymerization reaction zonel in proportions such that, during the course of the reaction in said polymerization reaction zone, the mole ratio of hydrogen bromide to dissolved aluminum bromide will be between about 0.05 and 1.8, the rate of addition of l-pentene to dissolved aluminum bromide will be not greater than about 4 moles per mole of dissolved aluminum bromide per minute, and the amount of l-pentene will be between about 5 and 90 moles per mole of dissolved aluminum bromide, and maintaining said polymerization reaction zone at a temperature of between about 0 C. and 40 C.

7. 'I'he process of claim 6 wherein the temperature is between about 15 C. and 35 C.

8. The process of claim 6 wherein the temperature is about 30 C.

9. A process for effecting the polymerization of an olefin having the formula.

R-CH=CH:

wherein R, is an alkyl group having at least two carbon atoms. which comprises adding said olefin to aluminum bromide dissolved in a nonpolymerizing hydrocarbon solvent at a rate not greater than about 4 moles of olefin per mole of dissolved aluminum bromide per minute and in an amount of between about 5 and 90 moles of olen per mole of dissolved aluminum bromide, said dissolved aluminum bromide containing hydrogen bromide in an amount of between about 0.05 and 1.6 moles per mole of dissolved aluminum bromide.

10. A process for enecting the polymerization of an olefin having the formula R-CH==CH2 wherein R is an alkyl group having at least two carbon atoms, which comprises adding said olefin to aluminum bromide dissolved in a non-polymerizing hydrocarbon solvent at a rate not greater than about 2.5 moles of olefin per mole of dissolved aluminum bromide per minute and in an amount of between about 20 and 75 moles of olefin per mole of dissolved aluminum bromide, said dissolved aluminum bromide containing hydrogen bromide in an amount of between about 0.08 and 1.2 moles per mole of dissolved aluminum bromide.

11. A polymer of an olen having the formula R-CH=CH2 wherein R is an alkyl group having at least two carbon atoms, obtained by the process which comprises adding said olen to aluminum bromide dissolved in a non-polymerizing hydrocarbon solvent at a rate not greater than about 4 moles of olefin per mole of dissolved aluminum bromide per minute and in an amount of between about 5 and moles of olen per mole of dissolved aluminum bromide, said dissolved aluminum bromide containing hydrogen bromide in an amount of between about 0.05 and 1.6 moles per mole of dissolved aluminum bromide, and said polymer having a. thickening power at 210 F., obtained polymer in blend-:the per cent by weight of from the formula: the polymer blended with a base stock lubricating oil; TP 100 o kinematic viscosity of oil blend 21- polymer in blend gm kinematic viscosity of base oil l wherein Kinematic viscosity of oil blend=the viscosity in @no :thickening power at 210s E; centistokes of the blend of base stock lubricating oil and polymer at 210 F.; and Kinematic viscosity of base oil=the viscosity in centistokes of the base stock lubricating oil at polymer in blend=the per cent by weight oi l the polymer blended with a base stock lubricating oil;

kinematic viscosity of oi1b1cnd=uic viscosity in 210 Ff of between 5 and 23- ent toke of t blen f bas geurige oii nd pciigmcr ai :510 Ffasiick lum l. 14 A plymer of octenel Obtdmed by the Kinematic viscosity of base oil=tlie viscosity in plroceiss which cqmpnes addnig sald octene-l to ccnusiokcs of the base stock lubricating oii at .alim num bromde dssolved m a nonpolymer' 210., F" in excess of 5 izmg hydrocarbon solvent at a rate not greater than about 4 moles of octene-lper mole of dis- 12 A polymer of but-m64 Obtained by the solved aluminum bromide per minute and in an process which comprises adding said butene-l to amount 0f bef/Ween abOlf 5 and 90 moles 0f 0caiuminum bromide dissolved in a non-pc-iymeriztene-1 per mole of dissolved aluminum bromide. ing hydrocarbon solvent at a rate not greater at a temperature of between about 20 C. and than about 4 moles 0f butene-l per mole 0f dis- 35 C., Said dSSOlVed aluminum bIOlIlide COD- solved aluminum bromide per minute and in an taining hydrogen bromide in an amount of beamount of between about 5 and 90 moles of butween about 0.05 and 1.6 moles per mole of distene-1111er mole of dissolved aluminum bromide, solved aluminum bromide, and said polymer havat a temperature of between about 25C. and ing a thickening power at 210 F., obtained from C., said dissolved aluminum bromide conthe formula:

TP 100 v 10g kinematic viscositymooil blend 21 polymer in blend 1 kinematic viscosity of base oil taining hydrogen bromide in an amount of bewherein tween about 0.05 and 1.6 moles per mole of ds- Tpm thickenin g power at 210 F.; solved aluminum bromide, and said polymer hav polymer in b1 en d=the per Cent by Weight of ing a thickening power at 210 F., obtained from t the formula; he polymer blended with a base stock lubricating oil;

TP `100 kinematic viscosity of oil blend 21 polymer in blend gm kinematic viscosity of base oil wherein Kinematic viscosity of oil blend=the viscosity in Tpnmzthickenmg power at 210 F centistokes of the blend of base stock lubricatpolymer in blend=the per cent by weight of mg 011 and polymer at 210 F; and

Kinematic viscosity of base oi1=the vislcosit in d th bas to k lubri- Y ggolirlrier blen ed W1 a e s c 4U centistokes of the base stock lubricating oil at Kincmatic viscosity of oii bicnd=uic viscosity in 210 F, 0f between 5 and 23- centistokes of the blend of base stock lubricating ou and polymer at 210 E; and 15. A mineral lubricating oil containing a tion sullicient to improve the vis- Kmematic viscosity of base oil=the viscosity 1n muior Propor centistokes oi the base stock lubricating oil at life? rthelieof of a polymer of an olefin 210 rx, of between 5 and 23. g e o mu a 13. A polymer of pentene-l obtained by the i R-CH=CH2 process which comprises adding said pentene-l to aluminum bromide dissolved in a non-polymcrwherein R is `an alkyl group having at 'least two zing hydrocarbon solvent at a rate not greater carbon atoms, obtained by the process which comthan about 4 moles of pentene-l per mole of disprises adding said olefin to aluminum bromide solved aluminum bromide per minute and in an dissolved in a non-polymerizing hydrocarbon solamount of between about 5 and 90 mOleS 0f D611- vent at a rate not greater than about 4 moles of tene-1 per mole of dissolved aluminum bromide, 60 olefin per mole of dissolved aluminum bromide at a temperature of between about 0 C. and -40 per minute and in an amount of between about 5 C., said dissolved aluminum bromide containing and moles of olen per mole of dissolved alumihydrgen bromide in an amount of between about num bromide, said dissolved aluminum. bromide 0.05 and 1.6 moles per mole of dissolved aluminum containing hydrogen bromide in an amount of bromide, and said polymer having a thickening b5 between about 0.05 and 1.6 moles per mole of dis- Dower at 210 F., obtained from the formular solved aluminum bromide, and said polymer havkinematic viscosity of oil blend TPM: polymer in blend Og kinematic viscosity of base oil Wherem ing a thickening power at 210 F., obtained from TP21o=thiCkening power at 210 F.; the formula:

TPM: 100 10g kinematic viscosity oi oil blend polymer in blend 1 kinematic viscosity of base oil 16. A mineral lubricating oil containing a -minor proportion, sulcient to improve the viscosity index thereof, of a. polymer of butene-l obtained by the process which comprises adding said butene-l to aluminum bromide dissolved in a non-polymerizing hydrocarbon solvent at a rate not greater than about 4 moles of butene-l per mole of dissolved aluminum bromide per minute and in an amount of between about 5I and 90 moles of butene-l per mole of dissolved aluminum bromide,at a temperature oi betweenV about 25 C. and 40 C., said dissolved alumi .num bromide containing hydrogen bromide in an amount of between about 0.05 and 1.6 moles per mole of dissolved aluminum bromide, and

said polymer having a thickening power at 210 i7., obtained from the formula:

20 wherein TPam=thiciiening power at 210 F.;

% polymer in blend=the per cent by weight of the polymer blended with a. base stock lubricating oil;

Kinematic viscosity of oil blend=the viscosity in centistokes of the blend of base stock lubricating oil and polymer at 210 F.; and

Kinematic viscosity of base oil=the viscosity in centistokes of the base stock lubricating oil at 210 F., of between 5 and 23.

i8. A mineral lubricating oil containing a minor proportion, -sumcient to improve the viscosity index thereof, of a polymer of octene-l obtained by the process which comprises adding said octene-l to aluminum bromide dissolved in a non-polymerizing hydrocarbon solvent at a rate not greater than about 4 moles of octene-l per mole of dissolved aluminum bromide per minute and in an amount of between about 5 and 90 moles of octene-l per mole of dissolved aluminum bromide, at a temperature of between about 20 C. and 35 C., said dissolved aluminum bromide containing hydrogen bromide in an amount of between about 0.05 and 1.6 moles per mole of dissolved aluminum bromide, and said polymer having a thickening power at 210 F., obtained from tbe formule.:

100 .kinematic viscosity of oil blend J am: polymer in blend 10g kinematic viscosity of base oil wherein W21o=tliicirening power at .210

kinematic viscosity of oil blend wherein TPzio=thickening power at 210 F.;

% polymer in blend=the per cent by weight of the polymer blended with. a base stock lubri eating oil;

Kinematic viscosity oi oil blend=the viscosity in centistokes of the blend of base stock lubricating oil and polymer at 21.0 iF.; and

Kinematic viscosity of base oil=the viscosity in eentistokes of the base stock lubricating oil at 210 F., of between 5 and 23.

17. A mineral lubricating oil containing a minor proportion, suicient to improve the viscosity index thereof, of a polymer oi pentene-l obtained by the process which comprises adding said pentene-l to aluminum bromide dissolved in a non-polymerizing hydrocarbon solvent at a rate not greater than about 4 moles of pentene-l per mole of dissolved aluminum bromide per minute and in an amount of between about 5 and 90 moles of pentene-l per mole of dissolved n aluminum bromide, at a temperature of between about 0 C. and 40 C., said dissolved aluminum bromide containing hydrogen bromide in an amount of between about 0.05 and 1.6 moles per mole of dissolved aluminum bromide, and said polymer having a thickening power at 210 F., obtained from the formula dil % polymer in blend il kinematic viscosity of base oil i polymer in blend=the per cent by weight of the polymer blended with a base stock lubricating oil;

.inematic viscosity of oil blend=the viscosity in centistokes of the blend of base stock lubricating oil and polymer at 210 F.; and

Kinematic viscosity of base oi1=the viscosity in centistokes of the base stock lubricating oil at 219 F., of between 5 and 23.

CELES'IE M. FONTANA. GLENN A. KIDDER.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,243,658 Thomas May 27, 1941 2,387,784 Thomas Oct. 30, 1945 2,401,933 Hershberger June 11, 1946 2,410,885 Lieber Nov. 12, 1946 2,471,890 Palmer May 31, 1949 2,474,670 Hershberger June 28, 1949 FOREIGN PATENTS Number Country Date 565,974 Great Britain Dec. 7, 1944 kinematic viscosity of oil blend 21"=% polymer in blend ogm kinemaric viscosity of base oil 

15. A MINERAL LUBRICATING OIL CONTAINING A MINOR PROPORTION, SUFFICIENT TO IMPROVE THE VISCOSITY INDEX THEREOF, A POLYMER OF AN OLEFIN HAVING THE FORMULA 